Tube splitting apparatus



United States Patent Ofiice TUBE SPLI'ITINGAPPARATUS Charles E. and William E. Cawley, Richland, Wash, assignors to the United States of America as represented by the United States Atomic Energy Commission Filed Dec. 3, 1959, Ser. No. 857,241

3 Claims. (Cl. 30-91) This invention relates to an apparatus for facilitating removal of a tube from a mass of material in which it is lodged. More particularly it relates to a tube-splitting apparatus.

Figs. 37, 38, and 39 and columns 42, 43, and 44 of Fermi et a1. Patent 2,708,656, dated May 17, 1955, disclose a nuclear reactor comprising graphite moderator blocks, internally ribbed coolant tubes extending through the blocks, and jacketed fuel elements of natural uranium laid end to end in the coolant tubes so as to be cooled by water flowing through the tubes and over the elements. On occasion, the coolant tubes must be replaced, because they have become damaged by overheating or by growth of the fuel elements. Frequently the coolant tubes to be replaced are stuck in the moderator, and we have found it advantageous to split process tubes to facil itate their removal.

The novel apparatus of the present invention weakens a tube to be removed at diametrally opposed regions and splits the tube at the weakened regions while shaping the edges of the split tube halves into inwardly directed flanges, whereby to reduce the size of the split halves and thus enable them to be dislodged from the graphite moderator.

In the drawings:

' Fig. l is an elevational view, partly in section, of the novel tube-splitting apparatus of the present invention;

Fig.2 is a sectional view taken on the line 22 of Fig. l and showing how the apparatus weakens a tube; and

Fig. 3 is a sectional view taken on the line -33 of Fig. 1 and showing how the apparatus splits and flanges the tube.

The present apparatus comprises a guide body 10, a pair of opposed cutter wheels 11 rotatably mounted therein for weakening a tube 12, and-an I-shaped blade 13 attached to the body for splitting the tube 12 into halves and flanging the halves.

The body 10 has a main portion 14 which comprises end regions 15 of a diameter slightly less than the internal diameter of the tube 12 and an intermediate region 16 reduced in diameter below that of the end regions 15. The main portion 14 has four equally spaced longitudinal grooves 17, which receive four internal longitudinal ribs 17a of the tube 12. Equally spaced from the grooves 17 are two diametrally opposed channels 18, which extend longitudinally of the main portion 14 of the body 10. In the intermediate region 16 of the main portion 14, slots 19 extend from the channels 18 radially inwardly so as to merge and form a passage through the body 10. The slots 19 and channels. 18 accommodate the cutter wheels -11 which are rotatably mounted in the intermediate region 16 of the body 10 on pins 20 held in the body 10 by set screws 21. The cutter wheels 11 lie generally on a common plane in which the longitudinal axis of the body 10 lies, and rotates about axes perpendicular to said common plane. The cutter wheels 11 extend radially outward beyond the end regions 15 of the body 10 a small amount and penetrate the wall of the tube with- Patented May 9, 1961 out cutting through it. The longitudinal axis of the body i 10 is, of course, generally coincident with the axis of the The body 10 has a reduced bifurcated axial extension 22, in which the blade 13 is attached by bolts 23 in spaced relation to the main portion 14 of the body 10. The blade 13, being I-shaped as previously described, is formed of a leg 24 and flanges 25 at opposite sides of the leg 24. The end of the leg 24 facing the main portion 14 of the body 10 is recessed and cham-fered at opposite sides of the extension 22 as indicated at 26 so as to present two cutting edges 27, which meet the flanges 25 in acute angles and decrease in sharpness as they approach the flanges 25.

The tube splitter of the present invention may be pulled through the tube 10 by a cable (not shown) that is connected with the tube splitter by a connecting device 28, which is fully shown and claimed in our copending application Serial No. 857,241, filed December 3, 1959. The connecting device is so constructed that any untwisting of the cable (not shown) due to its pulling the present tube splitter will not be transmitted as a rotating force to the tube splitter. Moreover, the connecting device 28 has a reduced threaded extension 29 which is removably connected to the body 10 so that the device 28 and cable (not shown) can be disconnected from the present tube splitter by a compressive end thrust on the cable and rotation of the cable and the device 28, as fully disclosed in our aforementioned copending patent application, resulting in unscrewing of the extension 29 from the body 10. The cable and the device 28 are disconnected in this way from the present tube splitter in the event that it is. necessary to back the tube splitter out of the tube 10, because it has become stuck therein.

In operation, the present tube splitter is pulled through the tube 12 from right to left as viewed in Fig. 1. The internal ribs 17a of the tube 12 and the grooves 17 of! the splitter body 10 receiving the ribs keep the tube splitter from rotating. The cutter wheels 11 partially cut through the tube 12 and thus weaken it. Since the leg 24 of the I-shaped blade 13 is aligned with the cutter wheels 11, the cutting edges 27 of the leg 24 meet the weakened portions of the tube 12 and cut it there, and

the leg '24 and flanges 25 shape the tube as it is cut, whereby the tube is split into halves and the edges of the halves are formed into inwardly directed flanges 30. The tube halves thus flanged occupy less space than the uncut tube 12 did and thus are easily dislodged from a hole in a graphite mass 3 1 by being shifted radially inward from the walls of the hole.

' It is also understood .that the invention is not to be limited by the details given herein but that it may be modified within the scope of the appended claims.

What is claimed is: 1. Apparatus for splitting a tube having internal longitudinal ribs in order to facilitate removal of the tube 7 from a graphite mass in which the tube is lodged, said apparatus comprising a guide body having longitudinal grooves adapted to receive the ribs of the tube, a pair of cutter wheels rotatably mounted in the same plane in the body so as to protrude from opposite sides thereof and an Lshaped blade attached to the body in longitudinally displaced relation to the cutter wheels, the stem of the I extending through the body in the same plane as the cutter wheels, and the flanges of the I being radially outward of the cutter wheels to a small extent.

2. Apparatus -for splitting a tube in order to facilitate removal of the tube from a graphite mass in which the v thereof, and an I-shaped blade attached to the body in longitudinally displaced relation to the cutter wheels, the stem of the I extending through the body in the same plane as the cutter wheels, and the flanges of the I being radially outward of the cutter wheels to a small extent.

3. The apparatus specified in claim 2, the guide body having longitudinal channels aligned with the cutter wheels and extending in opposite directions therefrom, the channels accommodating the passage of edge flanges on split halves of the tube produced by the I-shaped blade in the event that the apparatus becomes stuck while 5 splitting the tube and must be backed out of the tube.

No references cited. 

